Support cacheable request errors at execution (#642)

Author: sebas5384

src/GraphQL/Cache/CacheableRequestError.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Drupal\graphql\GraphQL\Cache;
+
+use GraphQL\Server\RequestError;
+use Drupal\Core\Cache\CacheableDependencyInterface;
+use Drupal\Core\Cache\RefinableCacheableDependencyTrait;
+
+/**
+ * Cacheable Request Error.
+ */
+class CacheableRequestError extends RequestError implements CacheableDependencyInterface {
+  use RefinableCacheableDependencyTrait;
+}

src/GraphQL/Execution/QueryProcessor.php

@@ -9,6 +9,7 @@
 use Drupal\Core\Session\AccountProxyInterface;
 use Drupal\graphql\Plugin\SchemaPluginManager;
 use Drupal\graphql\GraphQL\QueryProvider\QueryProviderInterface;
+use Drupal\graphql\GraphQL\Cache\CacheableRequestError;
 use GraphQL\Error\Error;
 use GraphQL\Error\FormattedError;
 use GraphQL\Executor\ExecutionResult;
@@ -200,6 +201,11 @@ protected function executeOperation(PromiseAdapter $adapter, ServerConfig $confi
 
       return $this->executeUncachableOperation($adapter, $config, $params, $document);
     }
+    catch (CacheableRequestError $exception) {
+      return $adapter->createFulfilled(
+        new QueryResult(NULL, [Error::createLocatedError($exception)], [], $exception)
+      );
+    }
     catch (RequestError $exception) {
       return $adapter->createFulfilled(new QueryResult(NULL, [Error::createLocatedError($exception)]));
     }